Semiconductor device

ABSTRACT

A semiconductor device has a semiconductor element provided with a functional surface on which a functional circuit is formed and with a back surface facing in the opposite direction to the functional surface, while also having a lead supporting the semiconductor element and electrically connected to the semiconductor element, and a resin package covering at least a portion of the semiconductor element and the lead. The semiconductor element has a functional surface side electrode formed on the functional surface and equipped with a functional surface side raised part that projects in the direction in which the functional surface faces. The functional surface side raised part of the functional surface side electrode is joined to the lead by solid state bonding.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a semiconductor device.

2. Description of Related Art

In a semiconductor device having a built-in semiconductor element, aconduction supporting member that constitutes a conduction path to thesemiconductor device and supports the semiconductor element is used. Insuch a semiconductor device, a lead made of a metal is used as theconduction supporting member. A plurality of wires made of Au or thelike are used as means for electrically connecting the semiconductorelement to the lead. Known documents relating to semiconductor devicesinclude JP-A-2014-7363, for example.

In the manufacturing process of the semiconductor device, a process forbonding the plurality of wires is executed. This bonding process isperformed sequentially on the plurality of wires, and cannot be executedcollectively on the plurality of wires. This is thus an impediment toimproving the manufacturing efficiency of the semiconductor device.Also, the wires are comparatively thin, and thus could possibly beunintentionally cut or separate during the manufacturing process of thesemiconductor device or use of the semiconductor device. Also, in thecase of joining the semiconductor device to a heat dissipation membercalled an island or the like, the semiconductor device and the heatdissipation member are joined via a joining material. Improvedefficiency and increased reliability of this junction are desired.

SUMMARY OF THE INVENTION

The present invention has been proposed under the above circumstances,and an object of the present invention is to provide a semiconductordevice that can enhance manufacturing efficiency and enables thesemiconductor element to be more reliably joined to the conductionconnection member. Also, another object of the present invention is toprovide a semiconductor device that can enhance manufacturing efficiencyand enables the semiconductor element to be more reliably joined to theheat dissipation member.

A semiconductor device according to a first aspect of the presentinvention is provided with a semiconductor element having a functionalsurface on which a functional circuit is formed and a back surfacefacing in an opposite direction to the functional surface, a conductionsupporting member supporting the semiconductor element and electricallyconnected to the semiconductor element, and a resin package at leastpartially covering the semiconductor element and the conductionsupporting member, the semiconductor element having a functional surfaceside electrode formed on the functional surface and equipped with afunctional surface side raised part that projects in a direction inwhich the functional surface faces, and the functional surface sideraised part of the functional surface side electrode being joined to theconduction supporting member by solid state bonding.

Preferably, the functional surface side electrode has a base layer thatcontacts the functional surface.

Preferably, the base layer is made of Al.

Preferably, the functional surface side raised part and the base layerdo not overlap with each other in plan view.

Preferably, the functional surface side electrode has a foundation layerlaminated on the base layer.

Preferably, the foundation layer is made of one of Ti, W and Ta.

Preferably, the functional surface side electrode has a redistributionlayer laminated on the foundation layer, and the functional surface sideraised part is formed on the redistribution layer.

Preferably, the redistribution layer is made of Cu.

Preferably, the redistribution layer is larger than the base layer inplan view.

Preferably, the functional surface side electrode has a joiningpromotion layer that is positioned as an uppermost layer.

Preferably, the joining promotion layer of the functional surface sideelectrode contains at least one of Ni and Pd.

Preferably, the joining promotion layer of the functional surface sideelectrode has a Ni layer laminated on the functional surface side raisedpart and a Pd layer laminated on the Ni layer.

Preferably, the semiconductor device is provided with a passivation filmcovering the functional surface and having formed therein a through holethat allows the functional surface side electrode to reach thefunctional surface.

Preferably, the passivation film is made of SiN.

Preferably, the redistribution layer overlaps with the passivation filmin plan view.

Preferably, the functional surface side raised part overlaps with thepassivation film in plan view.

Preferably, the semiconductor device is provided with a protective filmlaminated on the passivation film.

Preferably, the protective film is made of polyimide.

Preferably, the redistribution layer overlaps with the protective filmin plan view.

Preferably, the functional surface side raised part overlaps with theprotective film in plan view.

Preferably, the functional surface side raised part is made of Cu.

Preferably, the conduction supporting member is a lead made of a metal.

Preferably, a portion of the lead projects from the resin package.

Preferably, a surface of the lead on an opposite side to a region wherethe lead is joined to the functional surface side electrode hasunevenness.

Preferably, the semiconductor device has a plurality of the functionalsurface side electrode.

Preferably, the functional surface side electrode has a plurality of thefunctional surface side raised part.

Preferably, the semiconductor device is further provided with a heatdissipation member joined to the semiconductor element, thesemiconductor element has a back surface metal layer formed on the backsurface, and the back surface metal layer of the semiconductor elementis joined to the heat dissipation member by solid state bonding.

Preferably, a joining promotion layer is laminated on the back surfacemetal layer.

Preferably, the joining promotion layer on the back surface metal layercontains at least one of Ni and Pd.

Preferably, a joining promotion layer is laminated on the heatdissipation member.

Preferably, the joining promotion layer on the heat dissipation membercontains at least one of Ni and Pd.

Preferably, a surface of the heat dissipation member on an opposite sideto a region where the heat dissipation member is joined to the backsurface metal layer has unevenness.

Preferably, a surface of the heat dissipation member on an opposite sideto a region where the heat dissipation member is joined to the backsurface metal layer is exposed from the resin package.

A semiconductor device according to a second aspect of the presentinvention is provided with a semiconductor element having a functionalsurface on which a functional circuit is formed and a back surfacefacing in an opposite direction to the functional surface, a conductionsupporting member supporting the semiconductor element and electricallyconnected to the semiconductor element, and a resin package at leastpartially covering the semiconductor element and the conductionsupporting member, the semiconductor element having a functional surfaceside electrode formed on the functional surface, the conductionsupporting member having a conduction supporting member side raised partthat projects toward the functional surface side electrode, and thefunctional surface side electrode being joined to the conductionsupporting member side raised part of the conduction supporting memberby solid state bonding.

Preferably, the functional surface side electrode has a base layer thatcontacts the functional surface.

Preferably, the base layer is made of Al.

Preferably, the conduction supporting member side raised part and thebase layer do not overlap with each other in plan view.

Preferably, the functional surface side electrode has a foundation layerlaminated on the base layer.

Preferably, the foundation layer is made of one of Ti, W and Ta.

Preferably, the functional surface side electrode has a redistributionlayer laminated on the foundation layer.

Preferably, the redistribution layer is made of Cu.

Preferably, the redistribution layer is larger than the base layer inplan view.

Preferably, the functional surface side electrode has a joiningpromotion layer that is positioned as an uppermost layer.

Preferably, the joining promotion layer of the functional surface sideelectrode contains at least one of Ni and Pd.

Preferably, the joining promotion layer of the functional surface sideelectrode has a Ni layer that is positioned on the functional surfaceside and a Pd layer laminated on the Ni layer.

Preferably, the semiconductor device is provided with a passivation filmcovering the functional surface and having formed therein a through holethat allows the functional surface side electrode to reach thefunctional surface.

Preferably, the passivation film is made of SiN.

Preferably, the redistribution layer overlaps with the passivation filmin plan view.

Preferably, the conduction supporting member side raised part overlapswith the passivation film in plan view.

Preferably, the semiconductor device is provided with a protective filmlaminated on the passivation film.

Preferably, the protective film is made of polyimide.

Preferably, the redistribution layer overlaps with the protective filmin plan view.

Preferably, the conduction supporting member side raised part overlapswith the protective film in plan view.

Preferably, the conduction supporting member is a lead made of a metal.

Preferably, a portion of the lead projects from the resin package.

Preferably, a surface of the lead on an opposite side to a region wherethe lead is joined to the functional surface side electrode hasunevenness.

Preferably, the conduction supporting member side raised part isconstituted by a portion that is thicker than a surrounding portion.

Preferably, the conduction supporting member side raised part has athrough hole formed therein.

Preferably, the conduction supporting member side raised part is formedfrom a bent portion of the conduction supporting member.

Preferably, the semiconductor device has a plurality of the functionalsurface side electrode.

Preferably, the functional surface side electrode is joined to theplurality of conduction supporting member side raised parts.

Preferably, the semiconductor device is further provided with a heatdissipation member joined to the semiconductor element, thesemiconductor element has a back surface metal layer formed on the backsurface, and the back surface metal layer of the semiconductor elementis joined to the heat dissipation member by solid state bonding.

Preferably, a joining promotion layer is laminated on the back surfacemetal layer.

Preferably, the joining promotion layer on the back surface metal layercontains at least one of Ni and Pd.

Preferably, a joining promotion layer is laminated on the heatdissipation member.

Preferably, the joining promotion layer on the heat dissipation membercontains at least one of Ni and Pd.

Preferably, a surface of the heat dissipation member on an opposite sideto a region where the heat dissipation member is joined to the backsurface metal layer has unevenness.

Preferably, a surface of the heat dissipation member on an opposite sideto a region where the heat dissipation member is joined to the backsurface metal layer is exposed from the resin package.

A semiconductor device according to a third aspect of the presentinvention is provided with a semiconductor element having a functionalsurface on which a functional circuit is formed and a back surfacefacing in an opposite direction to the functional surface, a conductionsupporting member supporting the semiconductor element and electricallyconnected to the semiconductor element, a heat dissipation member joinedto the semiconductor element, and a resin package at least partiallycovering the semiconductor element, the conduction supporting member andthe heat dissipation member, the semiconductor element having a backsurface metal layer formed on the back surface, and the back surfacemetal layer of the semiconductor element being joined to the heatdissipation member by solid state bonding.

Preferably, a joining promotion layer is laminated on the back surfacemetal layer.

Preferably, the joining promotion layer on the back surface metal layercontains at least one of Ni and Pd.

Preferably, a joining promotion layer is laminated on the heatdissipation member.

Preferably, the joining promotion layer on the heat dissipation membercontains at least one of Ni and Pd.

Preferably, a surface of the heat dissipation member on an opposite sideto a region where the heat dissipation member is joined to the backsurface metal layer has unevenness.

Preferably, the semiconductor element has a functional surface sideelectrode formed on the functional surface.

Preferably, the functional surface side electrode is equipped with afunctional surface side raised part that projects in a direction inwhich the functional surface faces, and the functional surface sideraised part of the functional surface side electrode is joined to theconduction supporting member by solid state bonding.

Preferably, the conduction supporting member has a conduction supportingmember side raised part that projects toward the functional surface sideelectrode, and the functional surface side electrode is joined to theconduction supporting member side raised part of the conductionsupporting member by solid state bonding.

Preferably, the functional surface side electrode has a base layer thatcontacts the functional surface.

Preferably, the base layer is made of Al.

Preferably, the functional surface side electrode has a foundation layerlaminated on the base layer.

Preferably, the foundation layer is made of one of Ti, W and Ta.

Preferably, the functional surface side electrode has a redistributionlayer laminated on the foundation layer.

Preferably, the redistribution layer is made of Cu.

Preferably, the redistribution layer is larger than the base layer inplan view.

Preferably, the functional surface side electrode has a joiningpromotion layer that is positioned as an uppermost layer.

Preferably, the joining promotion layer of the functional surface sideelectrode contains at least one of Ni and Pd.

Preferably, the semiconductor device is provided with a passivation filmcovering the functional surface and having formed therein a through holethat allows the functional surface side electrode to reach thefunctional surface.

Preferably, the passivation film is made of SiN.

Preferably, the redistribution layer overlaps with the passivation filmin plan view.

Preferably, the semiconductor device is provided with a protective filmlaminated on the passivation film.

Preferably, the protective film is made of polyimide.

Preferably, the redistribution layer overlaps with the protective filmin plan view.

Preferably, the conduction supporting member is a lead made of a metal.

Preferably, a portion of the lead projects from the resin package.

Preferably, a surface of the lead on an opposite side to a region wherethe lead is joined to the functional surface side electrode hasunevenness.

Other features and advantages of the present invention will becomeapparent from the following detailed description with reference to theattached drawings.

BRIEF DESCRIPTION IN THE DIAGRAMS

FIG. 1 is a plan view showing a semiconductor device that is based on afirst embodiment of the present invention.

FIG. 2 is a bottom view showing the semiconductor device of FIG. 1.

FIG. 3 is a front view showing the semiconductor device of FIG. 1.

FIG. 4 is a side view showing the semiconductor device of FIG. 1.

FIG. 5 is a cross-sectional view along a line V-V in FIG. 1.

FIG. 6 is an enlarged cross-sectional view showing a main section of thesemiconductor device of FIG. 1.

FIG. 7 is an enlarged cross-sectional view showing a main section of anexemplary method for making the semiconductor device of FIG. 1.

FIG. 8 is an enlarged cross-sectional view showing a main section of anexemplary method for making the semiconductor device of FIG. 1.

FIG. 9 is an enlarged cross-sectional view showing a main section of anexemplary method for making the semiconductor device of FIG. 1.

FIG. 10 is an enlarged cross-sectional view showing a main section of anexemplary method for making the semiconductor device of FIG. 1.

FIG. 11 is an enlarged cross-sectional view showing a main section of anexemplary method for making the semiconductor device of FIG. 1.

FIG. 12 is an enlarged cross-sectional view showing a main section of anexemplary method for making the semiconductor device of FIG. 1.

FIG. 13 is a cross-sectional view showing an exemplary method for makingthe semiconductor device of FIG. 1.

FIG. 14 is an enlarged cross-sectional view showing a main section of anexemplary method for making the semiconductor device of FIG. 1.

FIG. 15 is a plan view showing a semiconductor device that is based on asecond embodiment of the present invention.

FIG. 16 is a bottom view showing the semiconductor device of FIG. 15.

FIG. 17 is a front view showing the semiconductor device of FIG. 15.

FIG. 18 is a side view showing the semiconductor device of FIG. 15.

FIG. 19 is a cross-sectional view along a line XIX-XIX in FIG. 1.

FIG. 20 is an enlarged cross-sectional view showing a main section ofthe semiconductor device of FIG. 15.

FIG. 21 is an enlarged cross-sectional view showing a main section of amodification of the semiconductor device of FIG. 15.

FIG. 22 is an enlarged cross-sectional view showing a main section ofanother modification of the semiconductor device of FIG. 15.

FIG. 23 is an enlarged cross-sectional view showing a main section ofanother modification of the semiconductor device of FIG. 15.

FIG. 24 is an enlarged cross-sectional view showing a main section ofanother modification of the semiconductor device of FIG. 15.

FIG. 25 is a plan view showing a semiconductor device that is based on athird embodiment of the present invention.

FIG. 26 is a bottom view showing the semiconductor device of FIG. 25.

FIG. 27 is a front view showing the semiconductor device of FIG. 25.

FIG. 28 is a side view showing the semiconductor device of FIG. 25.

FIG. 29 is a cross-sectional view along a line XXIX-XXIX in FIG. 25.

FIG. 30 is an enlarged cross-sectional view showing a main section ofthe semiconductor device of FIG. 25.

FIG. 31 is an enlarged cross-sectional view showing a main section of amodification of the semiconductor device of FIG. 25.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, preferred embodiments of the present invention will bedescribed with reference to the drawings.

FIGS. 1 to 6 show a semiconductor device that is based on a firstembodiment of the present invention. A semiconductor device A1 of thepresent embodiment is provided with leads 101 to 107, a semiconductorelement 300, and a sealing resin 400.

FIG. 1 is a plan view showing the semiconductor device A1. FIG. 2 is abottom view showing the semiconductor device A1. FIG. 3 is a front viewshowing the semiconductor device Al. FIG. 4 is a side view showing thesemiconductor device A1. FIG. 5 is a cross-sectional view along a lineV-V in FIG. 1. FIG. 6 is an enlarged cross-sectional view showing a mainsection of the semiconductor device A1.

The leads 101 to 107 are examples of a conduction supporting member asreferred to in the present invention. The leads 101 to 107 constituteconduction paths between the semiconductor element 300 and outside thesemiconductor device A1, and support the semiconductor element 300. Theleads 101 to 107 are made of a metal, and are preferably made of eitherCu or Ni, an alloy thereof, alloy 42, or the like. Also, a plating layerof Ti, Ag, Pd, Au or the like may be provided on the surface of theleads 101 to 107. The present embodiment will be described taking thecase where the leads 101 to 107 are made of Cu as an example. The leads101 to 107 are not particularly limited in thickness, and have, forexample, a thickness of 50 μm to 500 μm, and preferably 100 μm to 150μm.

The leads 101 to 107 each have an opposing part 110 and a terminal part120. The opposing part 110 overlaps with the semiconductor element 300in plan view, and opposes a functional surface side electrode 330 of thesemiconductor element 300 which will be discussed later. The terminalpart 120 is exposed from the sealing resin 400 and is used for mountingthe semiconductor device A1 to a circuit board or the like. As shown inFIGS. 3 and 5, the leads 101 to 107 have a bent part between theopposing part 110 and the terminal part 120. Also, the lead 101 has twoterminal parts 120.

As shown in FIG. 5, the opposing parts 110 have a joining surface 113and a back surface 114. The joining surfaces 113 face the functionalsurface side electrodes 330 of the semiconductor element 300, and arejoined to the functional surface side electrodes 330. The back surfaces114 face in the opposite direction to the joining surfaces 113.

As shown in FIGS. 2 and 6, the back surface 114 of the opposing part 110has unevenness. This uneven portion has a depth of about 20 μm, forexample.

In the present embodiment, as shown in FIG. 1, the terminal parts 120 ofthe leads 101, 104 and 106 project to the left in the diagram. Also, theterminal parts 120 of the leads 102, 103, 105 and 107 project to theright in the diagram. The opposing part 110 of the lead 101 iscomparatively large. The opposing parts 110 of the leads 102 and 103 aresmaller than the opposing part 110 of the lead 101, and are aligned inthe y direction. The opposing part 110 of the lead 101 is aligned in thex direction with the opposing parts 110 of the leads 102 and 103. Theopposing parts 110 of the leads 104, 105, 106 and 107 are comparativelysmall. The opposing parts 110 of the leads 106 and 107 are disposed soas to be aligned in the x direction toward the center in the xdirection. The opposing parts 110 of the leads 104 and 105 are disposedon either side in the x direction with the opposing parts 110 of theleads 106 and 107 sandwiched therebetween.

The semiconductor element 300 is an element that exhibits the functionsof the semiconductor device A1 and is not particularly limited in type,with it being possible to select from various types of elements such asa transistor, a diode or an LSI. As shown in FIG. 5, the semiconductorelement 300 has a functional surface 310 and a back surface 320. Theback surface 320 has formed thereon a functional circuit (not shown)that realizes the functions of the semiconductor element 300. The backsurface 320 faces in the opposite direction to the functional surface310. The semiconductor element 300 is manufactured from a wafer made ofSi or the like, for example.

The semiconductor element 300 has a plurality of functional surface sideelectrodes 330, a passivation film 340, and a protective film 350.

The plurality of functional surface side electrodes 330 are formed onthe functional surface 310 and are each electrically connected to adifferent one of the leads 101 to 107. In the present embodiment, sevenfunctional surface side electrodes 330 are formed in correspondence withthe leads 101 to 107. These functional surface side electrodes 330 havea common basic configuration despite differing in size and disposition.

In the present embodiment, as shown in FIG. 1, the functional surfaceside electrode 330 that opposes the opposing part 110 of the lead 101 iscomparatively large, and has an oblong shape in plan view with thelongitudinal direction being in the y direction. The two functionalsurface side electrodes 330 that oppose the opposing parts 110 of theleads 102 and 103 have a substantially square shape in plan view and arealigned in the y direction. The functional surface side electrode 330that opposes the opposing part 110 of the lead 101 is aligned in the xdirection with the two functional surface side electrodes 330 thatoppose the opposing parts 110 of the leads 102 and 103. The fourfunctional surface side electrodes 330 that oppose the opposing parts110 of the leads 104, 105, 106 and 107 are comparatively small and havea substantially square shape in plan view. The two functional surfaceside electrodes 330 that oppose the opposing parts 110 of the leads 106and 107 are disposed so as to be aligned in the x direction toward thecenter in the x direction. The two functional surface side electrodes330 that oppose the opposing parts 110 of the leads 104 and 105 aredisposed on either side in the x direction with the opposing parts 110of the leads 106 and 107 sandwiched therebetween.

As shown in FIGS. 1, 5 and 6, the functional surface side electrodes 330have a base layer 331, a foundation layer 332, a redistribution layer333, a functional surface side raised part 334, and a joining promotionlayer 335.

The base layer 331 contacts the functional surface 310, and iselectrically connected directly to an appropriate place of thefunctional circuit on the functional surface 310. The functional surface310 is made of Al, for example. The base layer 331 has a thickness of0.1 μm to 10 μm, for example.

Here, the passivation film 340 and the protective film 350 will bedescribed. The passivation film 340 is for preventing an excessive forcefrom being loaded on the Si which is a main constituent of thesemiconductor element 300, and is made of an insulating material such asSiN, for example. The passivation film 340 has a thickness of 200 nm to3 μm, for example. The protective film 350 is laminated on thepassivation film 340, and is for preventing an excessive force frombeing loaded on the Si which is a main constituent of the semiconductorelement 300 and for facilitating formation of the redistribution layer333. The protective film 350 is made of an insulating material such aspolyimide, for example. The protective film 350 has a thickness of about5 Tim, for example.

A through hole 341 is formed in the passivation film 340. The throughhole 341 is provided in order to expose the base layer 331 of thefunctional surface side electrode 330. In the present embodiment, theportion of the passivation film 340 surrounding the through hole 341covers an end edge of the base layer 331. A through hole 351 is formedin the protective film 350. The through hole 351 coincides with thethrough hole 341 in plan view, and is provided in order to expose thebase layer 331 of the functional surface side electrode 330.

Description will now return to the functional surface side electrodes330. The foundation layer 332 provides a foundation for forming theredistribution layer 333. The foundation layer 332 coincides in shapewith the functional surface side electrode 330 in plan view. That is,the foundation layer 332 covers the portion of the base layer 331exposed from the passivation film 340 and the protective film 350, thethrough hole 341 in the passivation film 340, the through hole 351 inthe protective film 350, and an appropriate region of the protectivefilm 350. The foundation layer 332 is made of Ti, TiW, Ta or the like,for example. The foundation layer 332 has a thickness of about 100 nm.

The redistribution layer 333 is a main constituent of the functionalsurface side electrode 330, and is larger than the base layer 331 inplan view. The redistribution layer 333 is not particularly limited inmaterial, and is made of Cu in the present embodiment. Theredistribution layer 333 has a thickness of about 10 μm, for example.

The functional surface side raised part 334 is formed on theredistribution layer 333 and projects in the direction in which thefunctional surface 310 faces. The functional surface side raised part334 is not particularly limited in material as long as the material is aconductive material, and is made of Cu in the present embodiment. Also,the functional surface side raised part 334 is not particularly limitedin shape, and has a columnar shape in the present embodiment. Thefunctional surface side raised part 334 has a diameter of 25 μm to 200μm and a height of 10 μm to 500 μm. In plan view, the functional surfaceside raised part 334 is disposed in a position that avoids the baselayer 331 so as to not overlap with the base layer 331. Also, thefunctional surface side raised part 334 overlaps with the passivationfilm 340 and the protective film 350 in plan view.

Also, in the present embodiment, as shown in FIG. 1, a plurality offunctional surface side raised parts 334 are formed on the threefunctional surface side electrodes 330 that oppose the opposing parts110 of the leads 101, 102 and 103. Eight functional surface side raisedparts 334 are formed in four rows and two columns on the functionalsurface side raised part 334 that opposes the opposing part 110 of thelead 101. Four functional surface side raised parts 334 are formed intwo rows and two columns on the functional surface side electrodes 330that oppose the opposing parts 110 of the leads 102 and 103. Onefunctional surface side raised part 334 each is formed on the functionalsurface side electrodes 330 that oppose the opposing parts 110 of theleads 104 to 107.

The joining promotion layer 335 constitutes the uppermost layer of thefunctional surface side electrode 330, and, in the present embodiment,covers the functional surface side raised parts 334 and theredistribution layer 333. The joining promotion layer 335 is forstrengthening the junction between the functional surface sideelectrodes 330 and the opposing parts 110 of the leads 101 to 107. Thejoining promotion layer 335 contains at least one of Ni and Pd, and, inthe present embodiment, consists of a Ni layer that directly covers thefunctional surface side raised parts 334 and the redistribution layer333 and a Pd layer laminated on this Ni layer. The joining promotionlayer 335 has a thickness of about 100 nm to 10 μm, for example. Also,apart from the materials given above, Cu, Al, Ti, Au or the like can beemployed as appropriate as the material of the joining promotion layer335.

The functional surface side electrodes 330 are joined to the opposingparts 110 of the leads 101 to 107 by solid state bonding. Morespecifically, the top faces of the functional surface side raised parts334 are solid state bonded to the joining surfaces 113 of the opposingparts 110. Note that, in the present embodiment, a configuration isadopted in which the joining promotion layer 335 is interposed betweenthe functional surface side raised parts 334 and the joining surfaces113 of the opposing parts 110. Note that a joining promotion layer maybe formed on the joining surfaces 113 of the opposing parts 110, inaddition to or instead of forming the joining promotion layer 335 on thefunctional surface side electrodes 330.

The sealing resin 400 entirely covers the semiconductor element 300 andcovers the leads 101 to 107 except for the terminal parts 120. Thesealing resin 400 is made of an insulating material, and, in the presentembodiment, is made of a black epoxy resin, for example. In the presentembodiment, the sealing resin 400 is also filled between the joiningsurfaces 113 of the opposing parts 110 and the joining promotion layers335 of the functional surface side electrodes 330, in areas avoiding thefunctional surface side raised parts 334.

Next, an exemplary method for making the semiconductor device A1 will bedescribed hereinafter.

First, as shown in FIG. 7, the base layer 331 is formed on thesemiconductor element 300. The base layer 331 is electrically connectedto an appropriate place of a functional circuit (not shown) formed onthe functional surface 310 of the semiconductor element 300. The baselayer 331 is patterned by plating using Al, for example. The base layer331 has a thickness of 0.1 μm to 10 μm, for example.

Next, as shown in FIG. 8, the passivation film 340 and the protectivefilm 350 are formed. Formation of the passivation film 340 and theprotective film 350 is performed by forming a SiN film and a polyimidefilm, for example, over the entire functional surface 310. The SiN filmhas a thickness of 200 nm to 3 μm, for example. Also, the polyimide filmhas a thickness of about 5 μm, for example. The through hole 341 and thethrough hole 351 that expose the base layer 331 are then formed in theSiN film and the polyimide film by patterning such as etching. Thepassivation film 340 and the protective film 350 are thereby obtained.

Next, as shown in FIG. 9, the foundation layer 332 is formed.Specifically, a film is made of Ti, TiW, Ta or the like and having athickness of about 100 nm is formed, so as to cover the portion of thebase layer 331 that is exposed from the passivation film 340 and theprotective film 350, the through hole 341, the through hole 351, and theprotective film 350. The film forming method is not particularlylimited, and CVD, spattering or the like can be used. Note that theshape, size and disposition of the foundation layer 332 correspond tothe shape, size and disposition of the functional surface sideelectrodes 330 to be formed.

Next, as shown in FIG. 10, the redistribution layer 333 is formed. Theredistribution layer 333 is formed by electrolytic plating using thefoundation layer 332, for example. The redistribution layer 333 is madeof Cu, for example, and has a thickness of about 10 μm. The shape, sizeand disposition of the redistribution layer 333 substantially match thefoundation layer 332.

Next, as shown in FIG. 11, the functional surface side raised parts 334are formed. The functional surface side raised parts 334 are formedthrough a combination of plating, sputtering and patterning, forexample. For example, a mask having openings that coincide with theshape of the functional surface side raised parts 334 in plan view isprepared, and Cu is adhered by plating or sputtering using this mask.Alternatively, the functional surface side raised parts 334 are formedby performing processing such as etching on a Cu film formed by platingor sputtering.

Next, as shown in FIG. 12, the joining promotion layer 335 is formed.Formation of the joining promotion layer 335 is performed bysequentially forming a Ni layer and a Pd layer by plating, for example,so as to cover the redistribution layer 333 and the functional surfaceside raised parts 334. The joining promotion layer 335 has a thicknessof 100 nm to 10 μm, for example.

Next, as shown in FIG. 13, the joining surfaces 113 of the opposingparts 110 of the leads 101 to 107 are joined to the plurality offunctional surface side electrodes 330 of the semiconductor element 300.This junction is realized by fixing the semiconductor element 300 to atable 801, and pressing a jig 802 against the back surfaces 114 of theopposing parts 110 of the leads 101 to 107, for example. A plurality ofprotrusions are formed in a lower surface of the jig 802 in the diagram.The jig 802 is vibrated in an xy plane, with a predetermined pressingforce being applied to the leads 101 to 107 by the jig 802. Thisvibration is low frequency compared with ultrasonic waves, for example,and is, for example, 100 Hz or less, and specifically 50 Hz to 60 Hz. Asshown in FIG. 14, the functional surface side raised parts 334 arethereby solid state bonded to the opposing parts 110 with the joiningpromotion layer 335 sandwiched therebetween. Also, the back surfaces 114of the opposing parts 110 are formed to have unevenness with the marksleft by the jig 802 having been pressed thereagainst.

Thereafter, the semiconductor device A1 is obtained by undergoing aprocess for forming the sealing resin 400.

Next, workings of the semiconductor device A1 will be described.

According to the present embodiment, the functional surface side raisedparts 334 are joined to the opposing parts 110 of the leads 101 to 107by solid state bonding. Solid state bonding involves both sides beingdirectly joined to each other and does not require a joining mediuminterposed between both sides, such as wire or solder. Also, the solidstate bonding of all of the functional surface side raised parts 334 andthe opposing parts 110 of the leads 101 to 107 can be performedcollectively. The manufacturing efficiency of the semiconductor deviceA1 can thereby be improved. Also, the joining strength of the functionalsurface side raised parts 334 with the opposing parts 110 of the leads101 to 107 can be enhanced.

As a result of providing the functional surface side raised parts 334,it is possible to reduce the area of the junction between the functionalsurface side electrodes 330 and the opposing parts 110 of the leads 101to 107. The force that needs to be applied in order to obtain apredetermined joining pressure at the time of solid state bonding canthereby be reduced. The semiconductor element 300 can thereby beprevented from being unintentionally damaged or the like. Also, as aresult of providing the functional surface side raised parts 334, thesealing resin 400 can be reliably filled between the functional surface310 of the semiconductor element 300 and the joining surfaces 113 of theopposing parts 110 of the leads 101 to 107. Places that need to beinsulated in the semiconductor device A1 can thereby be more reliablyinsulated.

As a result of the functional surface side raised parts 334 notoverlapping with the base layer 331 in plan view, it is possible toavoid the force at the time of solid state bonding being excessivelyloaded on the Si forming a main constituent of the semiconductor element300. Also, as a result of the functional surface side raised parts 334being overlapped with the passivation film 340 and the protective film350 in plan view, the force at the time of solid state bonding can beabsorbed by the passivation film 340 and the protective film 350.

As a result of providing the joining promotion layer 335, solid statebonding of the functional surface side raised parts 334 to the opposingparts 110 can be performed more reliably.

FIGS. 15 to 31 show other embodiments of the present invention. Notethat, in these diagrams, elements that are the same as or similar to theabove embodiment are given the same reference numerals.

FIGS. 15 to 20 show a semiconductor device that is based on a secondembodiment of the present invention. A semiconductor device A2 of thepresent embodiment is provided with leads 101 to 107, a semiconductorelement 300, and a sealing resin 400.

FIG. 15 is a plan view showing the semiconductor device A2. FIG. 16 is abottom view showing the semiconductor device A2. FIG. 17 is a front viewshowing the semiconductor device A2. FIG. 18 is a side view showing thesemiconductor device A2. FIG. 19 is a cross-sectional view along a lineXIX-XIX in FIG. 15. FIG. 20 is an enlarged cross-sectional view showinga main section of the semiconductor device A2.

The leads 101 to 107 are examples of a conduction supporting member asreferred to in the present invention. The leads 101 to 107 constituteconduction paths between the semiconductor element 300 and outside thesemiconductor device A2, and support the semiconductor element 300. Theleads 101 to 107 are made of a metal, and are preferably made of eitherCu or Ni, an alloy thereof, alloy 42, or the like. Also, a plating layerof Ti, Ag, Pd, Au or the like may be provided on the surface of theleads 101 to 107. The present embodiment will be described taking thecase where the leads 101 to 107 are made of Cu as an example. The leads101 to 107 are not particularly limited in thickness, and have, forexample, a thickness of 50 μm to 500 μm, and preferably 100 μm to 150μm.

The leads 101 to 107 each have an opposing part 110 and a terminal part120. The opposing part 110 overlaps with the semiconductor element 300in plan view, and opposes a functional surface side electrode 330 of thesemiconductor element 300 which will be discussed later. The terminalpart 120 is exposed from the sealing resin 400 and is used for mountingthe semiconductor device A2 to a circuit board or the like. As shown inFIGS. 17 and 19, the leads 101 to 107 have a bent part between theopposing part 110 and the terminal part 120. Also, the lead 101 has twoterminal parts 120.

As shown in FIG. 19, the opposing parts 110 have a joining surface 113and a back surface 114. The joining surface 113 faces the functionalsurface side electrode 330 of the semiconductor element 300. In thepresent embodiment, a conduction supporting member side raised part 111is formed on the joining surface 113 of the opposing part 110. Theconduction supporting member side raised part 111 projects toward thefunctional surface side electrode 330 from the joining surface 113. Theconduction supporting member side raised part 111 is not particularlylimited in shape, and, in the present embodiment, the conductionsupporting member side raised part 111 has a columnar shape. Theconduction supporting member side raised part 111 has a height of 25 μmto 200 μm and a diameter of 10 μm to 500 μm. Such a conductionsupporting member side raised part 111 can be formed by etching, forexample. The back surface 114 faces in the opposite direction to thejoining surface 113. As shown in FIGS. 16 and 20, the back surface 114of the opposing part 110 has unevenness. This uneven portion has a depthof about 20 μm, for example.

In the present embodiment, as shown in FIG. 15, the terminal parts 120of the leads 101, 104 and 106 project to the left in the diagram. Also,the terminal parts 120 of the leads 102, 103, 105 and 107 project to theright in the diagram. The opposing part 110 of the lead 101 iscomparatively large. The opposing parts 110 of the leads 102 and 103 aresmaller than the opposing part 110 of the lead 101, and are aligned inthe y direction. The opposing part 110 of the lead 101 is aligned in thex direction with the opposing parts 110 of the leads 102 and 103. Theopposing parts 110 of the leads 104, 105, 106 and 107 are comparativelysmall. The opposing parts 110 of the leads 106 and 107 are disposed soas to be aligned in the x direction toward the center in the xdirection. The opposing parts 110 of the leads 104 and 105 are disposedon either side in the x direction with the opposing parts 110 of theleads 106 and 107 sandwiched therebetween.

The semiconductor element 300 is an element that exhibits the functionsof the semiconductor device A2 and is not particularly limited in type,with it being possible to select from various types of elements such asa transistor, a diode or an LSI. As shown in FIG. 19, the semiconductorelement 300 has a functional surface 310 and a back surface 320. Theback surface 320 has formed thereon a functional circuit (not shown)that realizes the functions of the semiconductor element 300. The backsurface 320 faces in the opposite direction to the functional surface310. The semiconductor element 300 is manufactured from a wafer made ofSi or the like, for example.

The semiconductor element 300 has a plurality of functional surface sideelectrodes 330, a passivation film 340, and a protective film 350.

The plurality of functional surface side electrodes 330 are formed onthe functional surface 310 and are each electrically connected to adifferent one of the leads 101 to 107. In the present embodiment, sevenfunctional surface side electrodes 330 are formed in correspondence withthe leads 101 to 107. These functional surface side electrodes 330 havea common basic configuration despite differing in size and disposition.

In the present embodiment, as shown in FIG. 15, the functional surfaceside electrode 330 that opposes the opposing part 110 of the lead 101 iscomparatively large, and has an oblong shape in plan view with thelongitudinal direction being in the y direction. The two functionalsurface side electrodes 330 that oppose the opposing parts 110 of theleads 102 and 103 have a substantially square shape in plan view and arealigned in the y direction. The functional surface side electrode 330that opposes the opposing part 110 of the lead 101 is aligned in the xdirection with the two functional surface side electrodes 330 thatoppose the opposing parts 110 of the leads 102 and 103. The fourfunctional surface side electrodes 330 that oppose the opposing parts110 of the leads 104, 105, 106 and 107 are comparatively small and havea substantially square shape in plan view. The two functional surfaceside electrodes 330 that oppose the opposing parts 110 of the leads 106and 107 are disposed so as to be aligned in the x direction toward thecenter in the x direction. The two functional surface side electrodes330 that oppose the opposing parts 110 of the leads 104 and 105 aredisposed on either side in the x direction with the opposing parts 110of the leads 106 and 107 sandwiched therebetween.

As shown in FIGS. 15, 19 and 20, the functional surface side electrodes330 have a base layer 331, a foundation layer 332, a redistributionlayer 333, and a joining promotion layer 335.

The base layer 331 contacts the functional surface 310, and iselectrically connected directly to an appropriate place of thefunctional circuit on the functional surface 310. The functional surface310 is made of Al, for example. The base layer 331 has a thickness of0.1 μm to 10 μm, for example.

Here, the passivation film 340 and the protective film 350 will bedescribed. The passivation film 340 is for preventing an excessive forcefrom being loaded on the Si which is a main constituent of thesemiconductor element 300, and is made of an insulating material such asSiN, for example. The passivation film 340 has a thickness of 200 nm to3 μm, for example. The protective film 350 is laminated on thepassivation film 340, and is for preventing an excessive force frombeing loaded on the Si which is a main constituent of the semiconductorelement 300 and for facilitating formation of the redistribution layer333. The protective film 350 is made of an insulating material such aspolyimide, for example. The protective film 350 has a thickness of about5 μm, for example.

A through hole 341 is formed in the passivation film 340. The throughhole 341 is provided in order to expose the base layer 331 of thefunctional surface side electrode 330. In the present embodiment, theportion of the passivation film 340 surrounding the through hole 341covers an end edge of the base layer 331. A through hole 351 is formedin the protective film 350. The through hole 351 coincides with thethrough hole 341 in plan view, and is provided in order to expose thebase layer 331 of the functional surface side electrode 330.

Description will now return to the functional surface side electrodes330. The foundation layer 332 provides a foundation for forming theredistribution layer 333. The foundation layer 332 coincides in shapewith the functional surface side electrode 330 in plan view. That is,the foundation layer 332 covers the portion of the base layer 331exposed from the passivation film 340 and the protective film 350, thethrough hole 341 in the passivation film 340, the through hole 351 inthe protective film 350, and an appropriate region of the protectivefilm 350. The foundation layer 332 is made of Ti, TiW, Ta or the like,for example. The foundation layer 332 has a thickness of about 100 nm.

The redistribution layer 333 is a main constituent of the functionalsurface side electrode 330, and is larger than the base layer 331 inplan view. The redistribution layer 333 is not particularly limited inmaterial, and is made of Cu in the present embodiment. Theredistribution layer 333 has a thickness of about 10 μm, for example.

Note that, in plan view, the conduction supporting member side raisedpart 111 is disposed in a position that avoids the base layer 331 so asto not overlap with the base layer 331. Also, the conduction supportingmember side raised part 111 overlaps with the passivation film 340 andthe protective film 350 in plan view.

Also, in the present embodiment, as shown in FIG. 15, a plurality ofconduction supporting member side raised parts 111 are formed on theopposing parts 110 of the leads 101, 102 and 103. Eight conductionsupporting member side raised parts 111 are formed in four rows and twocolumns on the opposing part 110 of the lead 101. Four conductionsupporting member side raised parts 111 are formed in two rows and twocolumns on the opposing parts 110 of the leads 102 and 103. Oneconduction supporting member side raised part 111 each is formed on theopposing parts 110 of the leads 104 to 107.

The joining promotion layer 335 constitutes the uppermost layer of thefunctional surface side electrode 330, and, in the present embodiment,covers the redistribution layer 333. The joining promotion layer 335 isfor strengthening the junction between the functional surface sideelectrodes 330 and conduction supporting member side raised parts 111 ofthe opposing parts 110 of the leads 101 to 107. The joining promotionlayer 335 contains at least one of Ni and Pd, and, in the presentembodiment, consists of a Ni layer that directly covers theredistribution layer 333 and a Pd layer laminated on this Ni layer. Thejoining promotion layer 335 has a thickness of about 100 nm to 10 μm,for example. Also, apart from the materials given above, Cu, Al, Ti, Auor the like can be employed as appropriate as the material of thejoining promotion layer 335.

The functional surface side electrodes 330 are joined to the opposingparts 110 of the leads 101 to 107 by solid state bonding. Morespecifically, the redistribution layer 333 of the functional surfaceside electrodes 330 is solid state bonded to the conduction supportingmember side raised parts ill of the opposing parts 110. Note that, inthe present embodiment, a configuration is adopted in which the joiningpromotion layer 335 is interposed between the redistribution layer 333and the conduction supporting member side raised parts 111 of theopposing parts 110. Note that a joining promotion layer may be formed onthe conduction supporting member side raised parts 111 of the opposingparts 110, in addition to or instead of forming the joining promotionlayer 335 on the functional surface side electrodes 330.

The sealing resin 400 entirely covers the semiconductor element 300 andcovers the leads 101 to 107 except for the terminal parts 120. Thesealing resin 400 is made of an insulating material, and, in the presentembodiment, is made of a black epoxy resin, for example. In the presentembodiment, the sealing resin 400 is also filled between the joiningsurfaces 113 of the opposing parts 110 and the joining promotion layers335 of the functional surface side electrodes 330, in an area avoidingthe conduction supporting member side raised parts 111.

According to the present embodiment, the functional surface sideelectrodes 330 are joined to the conduction supporting member sideraised parts 111 of the opposing parts 110 of the leads 101 to 107 bysolid state bonding. Solid state bonding involves both sides beingdirectly joined to each other and does not require a joining mediuminterposed between both sides, such as wire or solder. Also, the solidstate bonding of all of the functional surface side electrodes 330 andthe conduction supporting member side raised parts 111 of the opposingparts 110 of the leads 101 to 107 can be performed collectively. Themanufacturing efficiency of the semiconductor device A2 can thereby beimproved. Also, the joining strength of the functional surface sideelectrodes 330 with the opposing parts 110 of the leads 101 to 107 canbe enhanced.

As a result of providing the conduction supporting member side raisedparts 111, it is possible to reduce the area of the junction between thefunctional surface side electrodes 330 and the opposing parts 110 of theleads 101 to 107. The force that needs to be applied in order to obtaina predetermined joining pressure at the time of solid state bonding canthereby be reduced. The semiconductor element 300 can thereby beprevented from being unintentionally damaged or the like. Also, as aresult of providing the conduction supporting member side raised parts111, the sealing resin 400 can be reliably filled between the functionalsurface 310 of the semiconductor element 300 and the joining surfaces113 of the opposing parts 110 of the leads 101 to 107. Places that needto be insulated in the semiconductor device A2 can thereby be morereliably insulated.

As a result of the conduction supporting member side raised parts 111not overlapping with the base layer 331 in plan view, it is possible toavoid the force at the time of solid state bonding being excessivelyloaded on the Si forming a main constituent of the semiconductor element300. Also, as a result of the conduction supporting member side raisedparts 111 being overlapped with the passivation film 340 and theprotective film 350 in plan view, the force at the time of solid statebonding can be absorbed by the passivation film 340 and the protectivefilm 350.

As a result of providing the joining promotion layer 335, solid statebonding of the functional surface side raised parts 334 to the opposingparts 110 can be performed more reliably.

FIGS. 25 to 30 show a semiconductor device that is based on a thirdembodiment of the present invention. A semiconductor device A3 of thepresent embodiment is provided with leads 101 to 107, a heat dissipationmember 200, a semiconductor element 300, and a sealing resin 400.

FIG. 25 is a plan view showing the semiconductor device A3. FIG. 26 is abottom view showing the semiconductor device A3. FIG. 27 is a front viewshowing the semiconductor device A3. FIG. 28 is a side view showing thesemiconductor device A3. FIG. 29 is a cross-sectional view along a lineXXIX-XXIX in FIG. 25. FIG. 30 is an enlarged cross-sectional viewshowing a main section of the semiconductor device A3.

The leads 101 to 107 are examples of a conduction supporting member asreferred to in the present invention. The leads 101 to 107 constituteconduction paths between the semiconductor element 300 and outside thesemiconductor device A3, and support the semiconductor element 300. Theleads 101 to 107 are made of a metal, and are preferably made of eitherCu or Ni, an alloy thereof, alloy 42, or the like. Also, a plating layerof Ti, Ag, Pd, Au or the like may be provided on the surface of theleads 101 to 107. The present embodiment will be described taking thecase where the leads 101 to 107 are made of Cu as an example. The leads101 to 107 are not particularly limited in thickness, and have, forexample, a thickness of 50 μm to 500 μm, and preferably 100 μm to 150μm.

The leads 101 to 107 each have an opposing part 110 and a terminal part120. The opposing part 110 overlaps with the semiconductor element 300in plan view, and opposes a functional surface side electrode 330 of thesemiconductor element 300 which will be discussed later. The terminalpart 120 is exposed from the sealing resin 400 and is used for mountingthe semiconductor device A3 to a circuit board or the like. As shown inFIGS. 27 and 29, the leads 101 to 107 have a bent part between theopposing part 110 and the terminal part 120. Also, the lead 101 has twoterminal parts 120.

As shown in FIG. 29, the opposing parts 110 have a joining surface 113and a back surface 114. The joining surfaces 113 face the functionalsurface side electrodes 330 of the semiconductor element 300, and arejoined to the functional surface side electrodes 330. The back surfaces114 face in the opposite direction to the joining surfaces 113.

As shown in FIGS. 26 and 30, the back surface 114 of the opposing part110 has unevenness. This uneven portion has a depth of about 20 μm, forexample.

In the present embodiment, as shown in FIG. 25, the terminal parts 120of the leads 101, 104 and 106 project to the left in the diagram. Also,the terminal parts 120 of the leads 102, 103, 105 and 107 project to theright in the diagram. The opposing part 110 of the lead 101 iscomparatively large. The opposing parts 110 of the leads 102 and 103 aresmaller than the opposing part 110 of the lead 101, and are aligned inthe y direction. The opposing part 110 of the lead 101 is aligned in thex direction with the opposing parts 110 of the leads 102 and 103. Theopposing parts 110 of the leads 104, 105, 106 and 107 are comparativelysmall. The opposing parts 110 of the leads 106 and 107 are disposed soas to be aligned in the x direction toward the center in the xdirection. The opposing parts 110 of the leads 104 and 105 are disposedon either side in the x direction with the opposing parts 110 of theleads 106 and 107 sandwiched therebetween.

The heat dissipation member 200 is joined to the semiconductor element300 and is for promoting dissipation of heat from the semiconductorelement 300. The heat dissipation member 200 is made of a metal, and ispreferably made of either Cu or Ni, an alloy thereof, alloy 42, or thelike. Also, a plating layer of Ti, Ag, Pd, Au or the like may beprovided on the surface of the heat dissipation member 200. The heatdissipation member 200 is not particularly limited in thickness, andhas, for example, a thickness of 50 μm to 500 μm, and preferably 100 μmto 150 μm. The present embodiment will be described taking the casewhere the heat dissipation member 200 is made of Cu and is formedtogether with the leads 101 to 107 as an example. In this case, in themanufacturing process of the semiconductor device A3, the leads 101 to107 and the heat dissipation member 200 are formed from the sameplate-like member. Also, in order to realize a disposition in which theleads 101 to 107 face the heat dissipation member 200 with thesemiconductor element 300 sandwiched therebetween, a technique in whichthe leads 101 to 107 are rotated 180 degrees relative to the heatdissipation member 200 about a rotation axis extending along the y axiscan be employed.

As shown in FIGS. 29 and 30, the heat dissipation member 200 has ajoining surface 210 and a back surface 220. The joining surface 210 isjoined to the semiconductor element 300. The back surface 220 faces inthe opposite direction to the joining surface 210. In the presentembodiment, the back surface 220 is exposed from the sealing resin 400.Also, as shown in FIGS. 25 and 30, the back surface 220 has unevenness.This uneven portion has a depth of about 20 μm, for example.

The semiconductor element 300 is an element that exhibits the functionsof the semiconductor device A3 and is not particularly limited in type,with it being possible to select from various types of elements such asa transistor, a diode or an LSI. As shown in FIG. 29, the semiconductorelement 300 has a functional surface 310 and a back surface 320. Theback surface 320 has formed thereon a functional circuit (not shown)that realizes the functions of the semiconductor element 300. The backsurface 320 faces in the opposite direction to the functional surface310. The semiconductor element 300 is manufactured from a wafer made ofSi or the like, for example.

The semiconductor element 300 has a plurality of functional surface sideelectrodes 330, a passivation film 340, a protective film 350, a backsurface metal layer 360, and a joining promotion layer 361.

The plurality of functional surface side electrodes 330 are formed onthe functional surface 310 and are each electrically connected to adifferent one of the leads 101 to 107. In the present embodiment, sevenfunctional surface side electrodes 330 are formed in correspondence withthe leads 101 to 107. These functional surface side electrodes 330 havea common basic configuration despite differing in size and disposition.

In the present embodiment, as shown in FIG. 25, the functional surfaceside electrode 330 that opposes the opposing part 110 of the lead 101 iscomparatively large, and has an oblong shape in plan view with thelongitudinal direction being in the y direction. The two functionalsurface side electrodes 330 that oppose the opposing parts 110 of theleads 102 and 103 have a substantially square shape in plan view and arealigned in the y direction. The functional surface side electrode 330that opposes the opposing part 110 of the lead 101 is aligned in the xdirection with the two functional surface side electrodes 330 thatoppose the opposing parts 110 of the leads 102 and 103. The fourfunctional surface side electrodes 330 that oppose the opposing parts110 of the leads 104, 105, 106 and 107 are comparatively small and havea substantially square shape in plan view. The two functional surfaceside electrodes 330 that oppose the opposing parts 110 of the leads 106and 107 are disposed so as to be aligned in the x direction toward thecenter in the x direction. The two functional surface side electrodes330 that oppose the opposing parts 110 of the leads 104 and 105 aredisposed on either side in the x direction with the opposing parts 110of the leads 106 and 107 sandwiched therebetween.

As shown in FIGS. 25, 29 and 30, the functional surface side electrodes330 have a base layer 331, a foundation layer 332, a redistributionlayer 333, a functional surface side raised part 334, and a joiningpromotion layer 335.

The base layer 331 contacts the functional surface 310, and iselectrically connected directly to an appropriate place of thefunctional circuit on the functional surface 310. The functional surface310 is made of Al, for example. The base layer 331 has a thickness of0.1 μm to 10 μm, for example.

Here, the passivation film 340 and the protective film 350 will bedescribed. The passivation film 340 is for preventing an excessive forcefrom being loaded on the Si which is a main constituent of thesemiconductor element 300, and is made of an insulating material such asSiN, for example. The passivation film 340 has a thickness of 200 nm to3 μm, for example. The protective film 350 is laminated on thepassivation film 340, and is for preventing an excessive force frombeing loaded on the Si which is a main constituent of the semiconductorelement 300 and for facilitating formation of the redistribution layer333. The protective film 350 is made of an insulating material such aspolyimide, for example. The protective film 350 has a thickness of about5 μm, for example.

A through hole 341 is formed in the passivation film 340. The throughhole 341 is provided in order to expose the base layer 331 of thefunctional surface side electrode 330. In the present embodiment, theportion of the passivation film 340 surrounding the through hole 341covers an end edge of the base layer 331. A through hole 351 is formedin the protective film 350. The through hole 351 coincides with thethrough hole 341 in plan view, and is provided in order to expose thebase layer 331 of the functional surface side electrode 330.

Description will now return to the functional surface side electrodes330. The foundation layer 332 provides a foundation for forming theredistribution layer 333. The foundation layer 332 coincides in shapewith the functional surface side electrode 330 in plan view. That is,the foundation layer 332 covers the portion of the base layer 331exposed from the passivation film 340 and the protective film 350, thethrough hole 341 in the passivation film 340, the through hole 351 inthe protective film 350, and an appropriate region of the protectivefilm 350. The foundation layer 332 is made of Ti, TiW, Ta or the like,for example. The foundation layer 332 has a thickness of about 100 nm.

The redistribution layer 333 is a main constituent of the functionalsurface side electrode 330, and is larger than the base layer 331 inplan view. The redistribution layer 333 is not particularly limited inmaterial, and is made of Cu in the present embodiment. Theredistribution layer 333 has a thickness of about 10 μm, for example.

The functional surface side raised part 334 is formed on theredistribution layer 333 and projects in the direction in which thefunctional surface 310 faces. The functional surface side raised part334 is not particularly limited in material as long as the material is aconductive material, and is made of Cu in the present embodiment. Also,the functional surface side raised part 334 is not particularly limitedin shape, and has a columnar shape in the present embodiment. Thefunctional surface side raised part 334 has a diameter of 25 μm to 200μm and a height of 10 μm to 500 μm. In plan view, the functional surfaceside raised part 334 is disposed in a position that avoids the baselayer 331 so as to not overlap with the base layer 331. Also, thefunctional surface side raised part 334 overlaps with the passivationfilm 340 and the protective film 350 in plan view.

Also, in the present embodiment, as shown in FIG. 25, a plurality offunctional surface side raised parts 334 are formed on the threefunctional surface side electrodes 330 that oppose the opposing parts110 of the leads 101, 102 and 103. Eight functional surface side raisedparts 334 are formed in four rows and two columns on the functionalsurface side raised part 334 that opposes the opposing part 110 of thelead 101. Four functional surface side raised parts 334 are formed intwo rows and two columns on the functional surface side electrodes 330that oppose the opposing parts 110 of the leads 102 and 103. Onefunctional surface side raised part 334 each is formed on the functionalsurface side electrodes 330 that oppose the opposing parts 110 of theleads 104 to 107.

The joining promotion layer 335 constitutes the uppermost layer of thefunctional surface side electrode 330, and, in the present embodiment,covers the functional surface side raised parts 334 and theredistribution layer 333. The joining promotion layer 335 is forstrengthening the junction between the functional surface sideelectrodes 330 and the opposing parts 110 of the leads 101 to 107. Thejoining promotion layer 335 contains at least one of Ni and Pd, and, inthe present embodiment, consists of a Ni layer that directly covers thefunctional surface side raised parts 334 and the redistribution layer333 and a Pd layer laminated on this Ni layer. The joining promotionlayer 335 has a thickness of about 100 nm to 10 μm, for example. Also,apart from the materials given above, Cu, Al, Ti, Au or the like can beemployed as appropriate as the material of the joining promotion layer335.

The functional surface side electrodes 330 are joined to the opposingparts 110 of the leads 101 to 107 by solid state bonding. Morespecifically, the top faces of the functional surface side raised parts334 are solid state bonded to the joining surfaces 113 of the opposingparts 110. Note that, in the present embodiment, a configuration isadopted in which the joining promotion layer 335 is interposed betweenthe functional surface side raised parts 334 and the joining surfaces113 of the opposing parts 110. Note that a joining promotion layer maybe formed on the joining surfaces 113 of the opposing parts 110, inaddition to or instead of forming the joining promotion layer 335 on thefunctional surface side electrodes 330.

The back surface metal layer 360 is formed on the back surface 320, and,in the present embodiment, entirely covers the surface of the backsurface 320. The back surface metal layer 360 is made of a metal, and ismade of Cu, Al, Ti, Au, or the like. The back surface metal layer 360has a thickness of 0.1 μm to 10 μm, for example.

The joining promotion layer 361 is laminated on the back surface metallayer 360. The joining promotion layer 361 contains at least one of Niand Pd, and, in the present embodiment, consists of a Ni layer thatdirectly covers the back surface 320 and a Pd layer laminated on this Nilayer. The joining promotion layer 361 has a thickness of about 100 nmto 10 μm, for example. Also, apart from the materials given above, Cu,Al, Ti, Au or the like can be employed as appropriate as the material ofthe joining promotion layer 361.

The back surface metal layer 360 is joined to the joining surface 210 ofthe heat dissipation member 200 by solid state bonding. In the presentembodiment, the joining promotion layer 361 is configured to beinterposed between the back surface metal layer 360 and the joiningsurface 210. The back surface 220 of the heat dissipation member 200 hasunevenness as described above due to the marks left by a jig beingpressed thereagainst at the time of solid state bonding the back surfacemetal layer 360 to the heat dissipation member 200.

The sealing resin 400 entirely covers the semiconductor element 300 andcovers the leads 101 to 107 except for the terminal parts 120. Thesealing resin 400 is made of an insulating material, and, in the presentembodiment, is made of a black epoxy resin, for example. In the presentembodiment, the sealing resin 400 is also filled between the joiningsurfaces 113 of the opposing parts 110 and the joining promotion layers335 of the functional surface side electrodes 330, in areas avoiding thefunctional surface side raised parts 334.

According to the present embodiment, the heat dissipation member 200 issolid state bonded to the back surface 320 of the semiconductor element300. An increase in the joining efficiency of the heat dissipationmember 200 with the back surface 320 of the semiconductor element 300can thereby be achieved, compared with the case where joining isperformed via a joining material, for example. Also, as a result ofperforming solid state bonding, the efficiency with which heat istransferred from the semiconductor element 300 to the heat dissipationmember 200 can be enhanced, and the dissipation of heat from thesemiconductor element 300 can be promoted.

The functional surface side raised parts 334 are joined to the opposingparts 110 of the leads 101 to 107 by solid state bonding. Solid statebonding involves both sides being directly joined to each other and doesnot require a joining medium interposed between both sides, such as wireor solder. Also, the solid state bonding of all of the functionalsurface side raised parts 334 and the opposing parts 110 of the leads101 to 107 can be performed collectively. The manufacturing efficiencyof the semiconductor device A3 can thereby be improved. Also, thejoining strength of the functional surface side raised parts 334 withthe opposing parts 110 of the leads 101 to 107 can be enhanced.

As a result of providing the functional surface side raised parts 334,it is possible to reduce the area of the junction between the functionalsurface side electrodes 330 and the opposing parts 110 of the leads 101to 107. The force that needs to be applied in order to obtain apredetermined joining pressure at the time of solid state bonding canthereby be reduced. The semiconductor element 300 can thereby beprevented from being unintentionally damaged or the like. Also, as aresult of providing the functional surface side raised parts 334, thesealing resin 400 can be reliably filled between the functional surface310 of the semiconductor element 300 and the joining surfaces 113 of theopposing parts 110 of the leads 101 to 107. Places that need to beinsulated in the semiconductor device A3 can thereby be more reliablyinsulated.

As a result of the functional surface side raised parts 334 notoverlapping with the base layer 331 in plan view, it is possible toavoid the force at the time of solid state bonding being excessivelyloaded on the Si forming a main constituent of the semiconductor element300. Also, as a result of the functional surface side raised parts 334being overlapped with the passivation film 340 and the protective film350 in plan view, the force at the time of solid state bonding can beabsorbed by the passivation film 340 and the protective film 350.

As a result of providing the joining promotion layer 335, solid statebonding of the functional surface side raised parts 334 to the opposingparts 110 can be performed more reliably.

FIG. 31 shows the modification of the semiconductor device A3. In thepresent modification, the conduction supporting member side raised parts111 described in relation to the semiconductor device A2 are formed onthe opposing parts 110, instead of forming the functional surface sideraised parts 334. An increase in the joining efficiency of the heatdissipation member 200 with the back surface 320 of the semiconductorelement 300 can also be achieved according to such a modification. Also,dissipation of heat from the semiconductor element 300 can be promoted.Also, the semiconductor device A3 may be the configuration to have boththe functional surface side raised parts 334 and the conductionsupporting member side raised parts 111.

The semiconductor device according to the present invention is notlimited to the abovementioned embodiments. Design changes can be freelymade to the specific configurations of the various parts of thesemiconductor device according to the present invention.

Configurations of the present invention and variations thereof areenumerated below as appendixes.

APPENDIX 1A

A semiconductor device comprising:

a semiconductor element having a functional surface on which afunctional circuit is formed and a back surface facing in an oppositedirection to the functional surface;

a conduction supporting member supporting the semiconductor element andelectrically connected to the semiconductor element; and

a resin package at least partially covering the semiconductor elementand the conduction supporting member,

wherein the semiconductor element has a functional surface sideelectrode formed on the functional surface,

the conduction supporting member has a conduction supporting member sideraised part that projects toward the functional surface side electrode,and

the functional surface side electrode is joined to the conductionsupporting member side raised part of the conduction supporting memberby solid state bonding.

APPENDIX 2A

The semiconductor device according to appendix 1A, wherein thefunctional surface side electrode has a base layer that contacts thefunctional surface.

APPENDIX 3A

The semiconductor device according to appendix 2A, wherein the baselayer is made of Al.

APPENDIX 4A

The semiconductor device according to appendix 2A, wherein theconduction supporting member side raised part and the base layer do notoverlap with each other in plan view.

APPENDIX 5A

The semiconductor device according to appendix 2A, wherein thefunctional surface side electrode has a foundation layer laminated onthe base layer.

APPENDIX 6A

The semiconductor device according to appendix 5A, wherein thefoundation layer is made of one of Ti, W and Ta.

APPENDIX 7A

The semiconductor device according to appendix 5A, wherein thefunctional surface side electrode has a redistribution layer laminatedon the foundation layer.

APPENDIX 8A

The semiconductor device according to appendix 7A, wherein theredistribution layer is made of Cu.

APPENDIX 9A

The semiconductor device according to appendix 7A, wherein theredistribution layer is larger than the base layer in plan view.

APPENDIX 10A

The semiconductor element according to any of appendix 7A, wherein thefunctional surface side electrode has a joining promotion layer that ispositioned as an uppermost layer.

APPENDIX 11A

The semiconductor device according to appendix 10A, wherein the joiningpromotion layer of the functional surface side electrode is made of atleast one of Ni and Pd.

APPENDIX 12A

The semiconductor device according to appendix 10A, wherein the joiningpromotion layer of the functional surface side electrode has a Ni layerthat is positioned on the functional surface side and a Pd layerlaminated on the Ni layer.

APPENDIX 13A

The semiconductor element according to appendix 7A, comprising apassivation film covering the functional surface and having formedtherein a through hole that allows the functional surface side electrodeto reach the functional surface.

APPENDIX 14A

The semiconductor device according to appendix 13A, wherein thepassivation film is made of SiN.

APPENDIX 15A

The semiconductor device according to appendix 13A, wherein theredistribution layer overlaps with the passivation film in plan view.

APPENDIX 16A

The semiconductor device according to appendix 13A, wherein theconduction supporting member side raised part overlaps with thepassivation film in plan view.

APPENDIX 17A

The semiconductor element according to appendix 13A, comprising aprotective film laminated on the passivation film.

APPENDIX 18A

The semiconductor device according to appendix 17A, wherein theprotective film is made of polyimide.

APPENDIX 19A

The semiconductor device according to appendix 17A, wherein theredistribution layer overlaps with the protective film in plan view.

APPENDIX 20A

The semiconductor device according to appendix 17A, wherein theconduction supporting member side raised part overlaps with theprotective film in plan view.

APPENDIX 21A

The semiconductor device according to appendix 1A, wherein theconduction supporting member is a lead made of a metal.

APPENDIX 22A

The semiconductor element according to appendix 21A, wherein a portionof the lead projects from the resin package.

APPENDIX 23A

The semiconductor device according to appendix 21A, wherein a surface ofthe lead on an opposite side to a region where the lead is joined to thefunctional surface side electrode has unevenness.

APPENDIX 24A

The semiconductor device according to appendix 21A, wherein theconduction supporting member side raised part is constituted by aportion that is thicker than a surrounding portion.

APPENDIX 25A

The semiconductor device according to appendix 24A, wherein theconduction supporting member side raised part has a through hole formedtherein.

APPENDIX 26A

The semiconductor device according to appendix 21A, wherein theconduction supporting member side raised part is formed from a bentportion of the conduction supporting member.

APPENDIX 27A

The semiconductor device according to appendix 1A, wherein thesemiconductor element has a plurality of the functional surface sideelectrode.

APPENDIX 28A

The semiconductor device according to appendix 1A, wherein thefunctional surface side electrode is joined to the plurality ofconduction supporting member side raised parts.

APPENDIX 29A

The semiconductor device according to appendix 1A, further comprising aheat dissipation member joined to the semiconductor element,

wherein the semiconductor element has a back surface metal layer formedon the back surface, and

the back surface metal layer of the semiconductor element is joined tothe heat dissipation member by solid state bonding.

APPENDIX 30A

The semiconductor device according to appendix 29A, wherein a joiningpromotion layer is laminated on the back surface metal layer.

APPENDIX 31A

The semiconductor device according to appendix 30A, wherein the joiningpromotion layer on the back surface metal layer is made of at least oneof Ni and Pd.

APPENDIX 32A

The semiconductor device according to appendix 29A, wherein a joiningpromotion layer is laminated on the heat dissipation member.

APPENDIX 33A

The semiconductor device according to appendix 32A, wherein the joiningpromotion layer on the heat dissipation member is made of at least oneof Ni and Pd.

APPENDIX 34A

The semiconductor device according to appendix 29A, wherein a surface ofthe heat dissipation member on an opposite side to a region where theheat dissipation member is joined to the back surface metal layer hasunevenness.

APPENDIX 35A

The semiconductor device according to appendix 29A, wherein a surface ofthe heat dissipation member on an opposite side to a region where theheat dissipation member is joined to the back surface metal layer isexposed from the resin package.

APPENDIX 1B

A semiconductor device comprising:

a semiconductor element having a functional surface on which afunctional circuit is formed and a back surface facing in an oppositedirection to the functional surface;

a conduction supporting member supporting the semiconductor element andelectrically connected to the semiconductor element;

a heat dissipation member joined to the semiconductor element; and

a resin package at least partially covering the semiconductor element,the conduction supporting member and the heat dissipation member,

wherein the semiconductor element has a back surface metal layer formedon the back surface, and

the back surface metal layer of the semiconductor element is joined tothe heat dissipation member by solid state bonding.

APPENDIX 2B

The semiconductor device according to appendix 1B, wherein a joiningpromotion layer is laminated on the back surface metal layer.

APPENDIX 3B

The semiconductor device according to appendix 2B, wherein the joiningpromotion layer on the back surface metal layer is made of at least oneof Ni and Pd.

APPENDIX 4B

The semiconductor device according to appendix 1B, wherein a joiningpromotion layer is laminated on the heat dissipation member.

APPENDIX 5B

The semiconductor device according to appendix 4B, wherein the joiningpromotion layer on the heat dissipation member is made of at least oneof Ni and Pd.

APPENDIX 6B

The semiconductor device according to appendix 1B, wherein a surface ofthe heat dissipation member on an opposite side to a region where theheat dissipation member is joined to the back surface metal layer hasunevenness.

APPENDIX 7B

The semiconductor device according to appendix 1B, wherein thesemiconductor element has a functional surface side electrode formed onthe functional surface.

APPENDIX 8B

The semiconductor device according to appendix 7B, wherein thefunctional surface side electrode is equipped with a functional surfaceside raised part that projects in a direction in which the functionalsurface faces, and

the functional surface side raised part of the functional surface sideelectrode is joined to the conduction supporting member by solid statebonding.

APPENDIX 9B

The semiconductor device according to appendix 7B, wherein theconduction supporting member has a conduction supporting member sideraised part that projects toward the functional surface side electrode,and

the functional surface side electrode is joined to the conductionsupporting member side raised part of the conduction supporting memberby solid state bonding.

APPENDIX 10B

The semiconductor device according to appendix 7B, wherein thefunctional surface side electrode has a base layer that contacts thefunctional surface.

APPENDIX 11B

The semiconductor device according to appendix 10B, wherein the baselayer is made of Al.

APPENDIX 12B

The semiconductor device according to appendix 10B, wherein thefunctional surface side electrode has a foundation layer laminated onthe base layer.

APPENDIX 13B

The semiconductor device according to appendix 12B, wherein thefoundation layer is made of one of Ti, W and Ta.

APPENDIX 14B

The semiconductor device according to appendix 12B, wherein thefunctional surface side electrode has a redistribution layer laminatedon the foundation layer.

APPENDIX 15B

The semiconductor device according to appendix 14B, wherein theredistribution layer is made of Cu.

APPENDIX 16B

The semiconductor device according to appendix 14B, wherein theredistribution layer is larger than the base layer in plan view.

APPENDIX 17B

The semiconductor device according to appendix 14B, wherein thefunctional surface side electrode has a joining promotion layer that ispositioned as an uppermost layer.

APPENDIX 18B

The semiconductor device according to appendix 17B, wherein the joiningpromotion layer of the functional surface side electrode is made of atleast one of Ni and Pd.

APPENDIX 19B

The semiconductor device according to appendix 14B comprising apassivation film covering the functional surface and having formedtherein a through hole that allows the functional surface side electrodeto reach the functional surface.

APPENDIX 20B

The semiconductor device according to appendix 19B, wherein thepassivation film is made of SiN.

APPENDIX 21B

The semiconductor device according to appendix 19B, wherein theredistribution layer overlaps with the passivation film in plan view.

APPENDIX 22B

The semiconductor device according to appendix 19B, comprising aprotective film laminated on the passivation film.

APPENDIX 23B

The semiconductor device according to appendix 22B, wherein theprotective film is made of polyimide.

APPENDIX 24B

The semiconductor device according to appendix 22B, wherein theredistribution layer overlaps with the protective film in plan view.

APPENDIX 25B

The semiconductor device according to appendix 1B, wherein theconduction supporting member is a lead made of a metal.

APPENDIX 26B

The semiconductor device according to appendix 25B, wherein a portion ofthe lead projects from the resin package.

APPENDIX 27B

The semiconductor device according to appendix 25B, wherein a surface ofthe lead on an opposite side to a region where the lead is joined to thefunctional surface side electrode has unevenness.

1. A semiconductor device comprising: a semiconductor element having afunctional surface on which a functional circuit is formed and a backsurface facing in an opposite direction to the functional surface; aconduction supporting member supporting the semiconductor element andelectrically connected to the semiconductor element; and a resin packageat least partially covering the semiconductor element and the conductionsupporting member, wherein the semiconductor element includes afunctional surface side electrode that is formed on the functionalsurface and equipped with a functional surface side raised partprojecting in a direction in which the functional surface faces, and thefunctional surface side raised part of the functional surface sideelectrode is joined to the conduction supporting member by solid statebonding.
 2. The semiconductor device according to claim 1, wherein thefunctional surface side electrode has abase layer that contacts thefunctional surface.
 3. The semiconductor device according to claim 2,wherein the base layer is made of Al.
 4. The semiconductor deviceaccording to claim 2, wherein the functional surface side raised partand the base layer do not overlap with each other in plan view.
 5. Thesemiconductor device according to claim 2, wherein the functionalsurface side electrode has a foundation layer laminated on the baselayer.
 6. The semiconductor device according to claim 5, wherein thefoundation layer is made of one of Ti, W and Ta.
 7. The semiconductordevice according to claim 5, wherein the functional surface sideelectrode has a redistribution layer laminated on the foundation layer,and the functional surface side raised part is formed on theredistribution layer.
 8. The semiconductor device according to claim 7,wherein the redistribution layer is made of Cu.
 9. The semiconductordevice according to claim 7, wherein the redistribution layer is largerthan the base layer in plan view.
 10. The semiconductor device accordingto claim 7, wherein the functional surface side electrode has a joiningpromotion layer that is positioned as an uppermost layer.
 11. Thesemiconductor device according to claim 10, wherein the joiningpromotion layer of the functional surface side electrode contains atleast one of Ni and Pd.
 12. The semiconductor device according to claim11, wherein the joining promotion layer of the functional surface sideelectrode has a Ni layer laminated on the functional surface side raisedpart and a Pd layer laminated on the Ni layer.
 13. The semiconductordevice according to claim 7, further comprising a passivation filmcovering the functional surface and having formed therein a through holethat allows the functional surface side electrode to reach thefunctional surface.
 14. The semiconductor device according to claim 13,wherein the passivation film is made of SiN.
 15. The semiconductordevice according to claim 13, wherein the redistribution layer overlapswith the passivation film in plan view.
 16. The semiconductor deviceaccording to claim 13, wherein the functional surface side raised partoverlaps with the passivation film in plan view.
 17. The semiconductordevice according to claim 13, further comprising a protective filmlaminated on the passivation film.
 18. The semiconductor deviceaccording to claim 17, wherein the protective film is made of polyimide.19. The semiconductor device according to claim 17, wherein theredistribution layer overlaps with the protective film in plan view. 20.The semiconductor device according to claim 17, wherein the functionalsurface side raised part overlaps with the protective film in plan view.21. The semiconductor device according to claim 1, wherein thefunctional surface side raised part is made of Cu.
 22. The semiconductordevice according to claim 1, wherein the conduction supporting member isa lead made of a metal.
 23. The semiconductor device according to claim22, wherein a portion the lead projects from the resin package.
 24. Thesemiconductor device according to claim 22, wherein a surface of thelead on an opposite side to a region where the lead is joined to thefunctional surface side electrode has unevenness.
 25. The semiconductordevice according to claim 1, wherein the semiconductor element has aplurality of the functional surface side electrode.
 26. Thesemiconductor device according to claim 1, wherein the functionalsurface side electrode has a plurality of the functional surface sideraised part.
 27. The semiconductor device according to claim 1, furthercomprising a heat dissipation member joined to the semiconductorelement, wherein the semiconductor element has a back surface metallayer formed on the back surface, and the back surface metal layer ofthe semiconductor element is joined to the heat dissipation member bysolid state bonding.
 28. The semiconductor device according to claim 27,wherein a joining promotion layer is laminated on the back surface metallayer.
 29. The semiconductor device according to claim 28, wherein thejoining promotion layer on the back surface metal layer contains atleast one of Ni and Pd.
 30. The semiconductor device according to claim27, wherein a joining promotion layer is laminated on the heatdissipation member.
 31. The semiconductor device according to claim 30,wherein the joining promotion layer on the heat dissipation membercontains at least one of Ni and Pd.
 32. The semiconductor deviceaccording to claim 27, wherein a surface of the heat dissipation memberon an opposite side to a region where the heat dissipation member isjoined to the back surface metal layer has unevenness.
 33. Thesemiconductor device according to claim 27, wherein a surface of theheat dissipation member on an opposite side to a region where the heatdissipation member is joined to the back surface metal layer is exposedfrom the resin package.